The carbon cycle is of fundamental importance to estimate the influence of anthropogenic emissions on the atmospheric CO2 concentration, and thus, to classify the impact of these emissions on global warming.
Different models have been developed, which under simplified assumptions can well reproduce the observed CO2 concentration over recent years, but they also lead to contradictory interpretations of the human impact. Here we consider, how far such suppositions are substantiated or must be made responsible for significant misinterpretations. We present detailed own calculations based on the Conservation Law, which reproduce all details of the measured atmospheric CO2 concentration over the Mauna Loa Era. In particular, they allow to deduce an upper limit of 35% for the anthropogenic contribution to the observed increase of CO2 over the Mauna Loa Era, and a more likely value of 14%. Under non-equilibrium conditions between the Earth’s surface and troposphere this even gives a lower bound of only 3.5%. The importance of only one unitary time scale for the removal of anthropogenic and natural CO2 emissions from the atmosphere, characterized by an effective absorption time, is discussed.
Continue reading: Understanding Increasing Atmospheric CO2 by Hermann Harde.